Prickly heat

Definition/diagnostic criteria Prickly heat, also known as miliaria, is a common skin condition resulting from the blockage of sweat ducts and subsequent inflammation. It is characterised by small red bumps and a prickling or stinging sensation on the skin. Prickly heat can affect anyone, regardless of age, but is particularly prevalent in infants and young children due to their underdeveloped sweat glands.

Epidemiology Prickly heat is commonly observed in hot and humid environments, affecting individuals of all ages, including infants and young children. The condition is more prevalent during the summer months and in tropical climates. The condition can affect individuals of all skin types.

Diagnosis
Clinical features: The diagnosis of prickly heat is primarily clinical, based on the characteristic appearance of the rash and the associated symptoms.

• The rash typically presents as small red bumps, which may be surrounded by areas of redness.
• In black and ethnic minority skin types, the redness may be less apparent, but the bumps and irritation will be noticeable.
• The bumps are usually accompanied by a prickling or stinging sensation.
• The rash commonly appears in areas of the body where sweat is trapped, such as the armpits, groin, under the breasts and in the folds of the skin.
• The condition is usually self-limiting, with symptoms resolving within a few days to a week.

Investigations: Investigations are not typically required.

Treatment The mainstay of treatment for prickly heat is the avoidance of sweating and heat exposure.

• Patients should be advised to stay in a cool environment, wear loose-fitting clothing, and use fans or air conditioning to reduce sweating.
• Topical treatments, such as calamine lotion or hydrocortisone cream, can be applied to the affected areas to help soothe the skin and reduce inflammation.
• Oral antihistamines may also be considered to help alleviate itching.

Prognosis Most cases resolve within a few days to a week with appropriate management. However, in some individuals, particularly those living in hot and humid climates, the condition may recur. Preventive measures, such as staying cool and avoiding excessive sweating, can help to reduce the risk of recurrence.